This module is meant to be the definitive implementation of
iterators, as popularized by Mark Jason Dominus's lectures and
recent book (_Higher Order Perl_, Morgan Kauffman, 2005).

An "iterator" is an object, represented as a code block that
generates the "next value" of a sequence, and generally
implemented as a closure.  Iterator.pm provides a class that
simplifies creation and use of these iterator objects.
